@cmb:
Not sure why it's only detecting one CPU.
Well fortunately after a firmware update of that Compaq both CPUs are detected (before they weren't even detected on Linux).
@cmb:
With a single 933 MHz CPU, ~210 Mb is obviously the best you can do on that hardware. Maxed out on interrupt load means your CPU is a bottleneck.
If you can get it to detect the second CPU, you should be able to push that over 300 Mb, but don't expect miracles out of CPU's that slow. If you need to firewall gigabit at wire speed, you're going to need a faster processor, even a dual 933 isn't going to cut it.
I can't believe that it won't get any faster than that with such hardware. After the second CPU got detected, we now reach 270 Mbits and interrupt CPU load is around 40-45%. (Each CPU around 40-45%) So what could it be that now slows the network?
@cmb:
On the CPU detection, first see if you can get a BIOS update and updates for any other firmware on the box. I would suggest searching for people's experiences with that hardware and FreeBSD 6.2, might find something useful that way. Also search here on the forum and on the mailing list archives.
Unfortunately there wasn't too many information on the net about compaq ml530 with freebsd 6+ .. but anyway at least the CPU problem is now solved.. Thanks for the hint, maybe you've got another one for the still somewhat "slow" network ..